Well blowout preventer



June 5, 1956 T. B. LosEY WELL BLOWOUT PREVENTER 5 Sheets-Sheet 2 Filed June 26, 1951 II I IN V EN TOR.

Thomas B Losey ATTORNEY June 5, 1956 T. B. LosEY 2,749,078

WELL BLOWOUT PREVENTER Filed June 26, 1951 5 Sheets-Sheet 3 A TTORN E Y J ne 1956 T. B. LOSEY WELL BLOWOUT PREVENTER 5 Sheets-Sheet 4 Filed June 26, 1951 EQMM JNVENTOR. 7

ATTORNEY Thomas B. Losey T. B. LOSE-Y WELL BLOWOUT PREVENTER 5 Sheets-Sheet Filed June 26, 1951 A TTORNEY United States Patent WELL BLOWOUT PREVENTER Thomas B. Losey, Dallas, Tex., assignor to The Guiberson Corporation, Dallas, Tex., a corporation of Delaware Application June 26, 1951, Serial No. 233,589

9 Claims. (Cl. 251-1) This invention is concerned with a blowout preventer to be used on an oil or gas well to confine and control the pressure therein.

This blowout preventer is essentially a valve designed to be attached to the upper end of the casing of an oil well for the purpose of closing off the pressure about a drill stem or tubing or other Well pipe carried within the casing. The device provides a seal to prevent the pressure within the casing from escaping.

This preventer employs an elongated hollow body or housing normally extending horizontally and having a vertical passage therethrough for well pipe. Complementary rams slide horizontally in the housing from oppo site ends thereof. Each ram carries a resilient sealing member or valve head, arranged to embrace and impinge against Well pipe (as tubing or drill stem) extending through the vertical opening in the housing. However, such resilient valve heads may be made as blanks which are solid members. When engaged or brought together, a pair of blanks will entirely close of]? the casing when no well pipe is positioned therein.

It is good practice to employ at least two blowout preventers, stacked one over the other. The lowermost preventer is attached to the casing and is provided with blank sealing members. The upper preventer is provided with sealing members having passages or openings therethrough to embrace the well pipe. When the well pipe (tubing or drill stem) is pulled from the casing during drilling operations or in production operations, then the bottommost preventer (being the blank carrying preventer) may be employed to entirely close olf the casing. Whenever desired, a plurality of such modified blowout preventers (carrying blanks) may be' stacked over one another and so arranged for the purpose of assuring positive seal of pressure and providing greatest safety;

Conventional blowout preventers employed in the past have had tall bulky housings which when placed in plural numbers, one over the other, were spaced apart and connected together by relatively tall flanged couplings or spools. Such usual construction materially increased the overall height of the assembly. Such preventers were installed at the top of the casing under the derrick floor. By reason of the great height of the dual installation of conventional preventers, the derrick floor frequently had to be raised. This decreased and lost the use of valuable derrick space. Great expenditures of money for materials and labor were simply lost in such installations.

In such old type preventers rams carrying some form of resilient sealing means were required to exactly fit the housings in which they were moved. This required excessive and precise machining of the ram and of the housing, thereby greatly increasing the cost of manufacture.

Some of the conventional rams were required to be hydraulically operated by fluid pressure supplied by costly pumps. Otherwise it would be impossible to move them against the well pressure. Other conventional preventers had to be tightly sealed so that no well pressure whatever could come into the body of the preventer. They were packed oil at top and bottom about the drill stem or tubing, in order to prevent well pressure from working against the ram and allow it to be moved manually.

Some makers of old style preventers, finding that neither the hydraulically driven ram nor the completely sealed oti body of an empty valve casing could be depended on to operate regularly, adopted both the sealed body and hydraulic power. This combination is doubly expensive, and still unsatisfactory. The body seals often failed to withstand the direct force of full well pressure, where upon the hydraulic rams were forced by the great well pressure into deflected positions under great stress. Distortion and damage to moving parts resulted. Then retraction of the rams became most difiicult.

The rams in these old type preventers were customarily andnecessarily made with sealing members of most exact and specific dimensions. Such was an absolute necessity in order to seal against a well pipe oflike dimension.

Therefore, it was necessary to change the entire ram assembly in order to adapt such a preventer for use with a well pipe of different size. The resilient members alone could not be changed to effect adaptation. The entire ram assembly had to be replaced with one capable of fitting against a smaller or larger well pipe. Labor cost in making replacements was excessive. The operator had to keep in stock a pair of rams for every pipe size to be encountered. A like stock was necessary for every separate conventional preventer used at the well site. Inventory cost was high. Labor and time lost in these changes could not be avoided in the earlier devices;

The present invention is designed to overcome indi-' cated ditiiculties in old devices and prior practices andamong the objects of this invention are the following:

a. To provide a blowout preventer that is low in height, lessening cellar space and increasing derrick space;

b. To provide a blowout preventer so constructed that a plural number thereof may be stacked and joined one over the other without any auxiliary equipment between them such as conventional flanges or spools, giving greater e. To provide a blowout preventer wherein the hollow body thereof lying all about the ram is subjected to well pressure, and the pressure is equalized thereabout at all times, as while the sealing element is out of sealing position, and also while it is moving into sealing position, and also while it is in sealed position, so that there is at no time any pressuure exerted or working against the progress of the sealing element while it is being moved to sealing position. On such design and structure the well pressure isemployed in the body as an asset, instead of being fought against as an evil.

1. To provide a blowout preventer wherein the sealing element carried by a universal slide may be easily and quickly changed without changing the entire slide assembly.

g. To provide a blowout preventer which may be adapted to different sizes of pipe by merely changing the rubber-like sealing element and its re-tainingplate, with- 3 out the necessity of changing the entire ram assembly, the latter carrying a pair of universal slides.

11. To provide a blowout preventer which may be installed one over the other and positively sealed together as a plural unit by special means which seals tighter as pressure is increased inside the preventer bodies, eliminating the usual flanges, spools and other couplings ordinarily used between bodies.

i. To provide complementary slides which also operate as guides in a blowout preventer being so arranged as to guide well pipe to the center of complementary sealing elements carried by such slides.

i. To provide a blowout preventer wherein resilient sealing elements carried by universal slides are effectively fed to and spread against the well pipe and other surfaces including the top of the body, to effect positive seals.

A. To provide a blowout preventer having slides therein spaced from the walls of the slideway and hollow body in which the slides move, so as to equalize fluid well pressure about the slides and permit them to be more easily moved within the body.

I. To provide a blowout preventer having a hollow body which may be washed and cleaned out through fluid wall ports, through which ports well fluid also may be circulated while the slide is either in or out of sealing position.

m. To provide a blowout preventer wherein a retainer plate is so arranged above a plastic or rubber-like sealing element as to permit the plate to move horizontally relative to the sealing element and allow the rubber-like material to feed and cold flow toward and about the pipe after the retainer plate has engaged the pipe.

The drawings present typical structures embodying this invention, in which:

Fig. I is a perspective view of a typical single blowout preventer valve, mounted on a well casing.

Fig. II is a diagrammatic elevational view of a dual unit blowout preventer valve assembly arranged in parallel relation.

Fig. III is a diagrammatic elevational view of a dual unit blowout preventer valve assembly arranged in crisscross relation.

Fig. IV is a sectionalized view of a typical valve taken along a. plane passing horizontally through the resilient sealing valve heads carried by the rams.

Fig. V is a partially sectionalized elevational view of a dual unit valve assembly arranged as shown in Fig. II.

Fig. VI is a sectionalized elevational view on one-half of a single valve, showing the ram retracted and lying loosely on its inclined track.

Fig. VII is a perspective view of a pair of complementary rams inverted and spaced apart.

Fig. VIII is a perspective view of a pair of comple mentary rams spaced apart and seen from above, with the retaining plate lifted above the right ram.

Fig. IX is a sectionalized elevational view of a fragment of the outer end of a retracted ram with a retaining pin loosely carrying a retaining plate which lies on the resilient valve head.

Fig. X is a sectionalized elevational view of a fragment of the outer end of an engaged ram with a retaining pin urged forwardly in its loose socket in the retaining plate shown in Fig. IX.

Fig. X1 is a plan view of a pair of rams in complementary engagement.

Fig. XII is a sectionalized elevational view of a pair of rams in engagement carrying blank resilient valve heads and blank retainer plates, such heads and plates being modified and made as solid members Without any passage openings therethrough.

In the drawings various parts of a device capable" of employing the instant invention have been indicated by numerals, like numerals being given to like parts.

A typical blowout preventer of the character here disclosed is in effect a giant valve of great strength. It

is provided with a. housing or valve body, shown as at 1. This body is an elongated hollow vessel, having a fiat top 1a, and a flat bottom 111. These members are supported and spaced apart by two parallel side walls 1c. The housing thus described can be made as a single unitary casting.

The great difiiculties of machining the inside of hollow bodies is well known. Such an operation is expensive. Interior machining has been reduced to a minimum in the design and construction of this blowout preventer valve.

The ends of the hollow body or valve casing 1 have been closed and capped by removable end plates 14. These plates may be secured to the body proper by the use of threaded machine screws 16, carried in threaded sockets arranged in the end faces of the body, at properly spaced intervals. Machine screws 16 pass through bolt holes 15 in end plates 14, and are capped and made up tight with nuts 17.

It is important that provision has been made for closely, compactly and firmly uniting together a multiple number. of valve bodies, arranged one above the other. In a multiple unit assembly each valve may be independently operated.

The separate valve bodies in a multiple valve assembly may be mounted in parallel as shown in Fig. 11, or they may be arranged in criss-cross relation as shown in Fig. III. Great pressure is allowed and carried within the valve body. Therefore, it is very important that there be no leaks in the connections between one valve body and another such body arranged above or below it. It is also important that the means uniting two valve bodies be of the strongest and most dependable kind, and yet be such as will allow quick and easy separation of the bodies when desired.

These ends are accomplished in the design of this invention as indicated in the drawings and particularly in Fig. I. Vertically through the side walls 10 of the valve body 1 there are provided stud holes 2. Added strength may be provided by having such holes pass through bosses 13a which may be added by being cast in spaced relation as a part of side walls 10. There may be provided along these bosses (or elsewhere about the valve body) external hook-like projections 13, whereby chains and cables may be used for lifting and lowering the body and the entire blowout preventer. It must be remembered that these units are very heavy; and multiple valve assemblies especially should have cable hooks.

It is to be noted as a matter of importance that the stud holes 2 lie entirely without and beyond the hollow space in the valve body. They do not extend into such space. These holes do not pass through the top In or the bottom 1b of the valve body. They are arranged entirely within the side walls 10 or in lateral extensions thereof. The reason for this will be made plain hereinafter.

Immediately at each end of holes 2, both top and bottom, there should be provided a slight extension of the side wall or boss material. Such added material will provide the vestigal and extremely short studs or legs 3, through which hole 2 will pass.

Studs 4 should be made of heavy steel rods of great strength. They are provided of such lengths as to pass entirely through a plurality of holes 2 arranged in align ment within the walls of two or more separate valve bodies which it is desired be united in a multiple valve unit, such as is shown in Fig. V. Where more than two valve units are to be put together, then stud 4 must be made of properly increased length. Both ends of studs 4 are threaded, and provided with nuts 4, which nuts are drawn up tight against stubs 3. One such stub is on top of the uppermost valve body and another is below the lowermost valve body.

It is recommended that four stud holes 2 be so spaced within the side walls of a single valve body that their 'a single unit carrying multiple valves.

body, preferably at the exact center of the top element 1a of valve housing or body 1. In exact alignment below such opening will be found an exactly like opening 6 arranged through the bottom 1b of the housing. When arranged as indicated, these openings or passages 6 will not only be in perfect alignment in one single valve body, but they will also be in perfect alignment in a series of valve units which have been stacked up and put together, either in parallel, as in Fig. II, or in crisscross relation, as in Fig. III.

As usually installed, the valve body is firmly'attached to the uppermost end of the well casing. Such attachment may be provided through the use of a conventional flanged nipple or coupling 10, on which the flange is indicated as at 11. Machine screws 12 pass through holes spaced about such flange. These screws are received in threaded sockets or holes 9 arranged in both the top and bottom faces of body 1. Holes 9 are arranged in a circlearound passageway 6 in the valve body. They may be employed with bolts or screws, as indicated above, for attaching a typical blowout preventer unit to the top of the well casing. Also they may be used to attach any auxiliary equipment, such as a drilling head, or any other piece of equipment desired to be connected with blowout preventers. However, these holes 9 are not needed and should not be used in connecting two blowout preventer bodies together to form A far more advantageous and safe method for making such connection is shown in the drawings and explained hereinafter.

Arranged in a circle lying around passage opening 6 in the valve body there is provided a V-shaped channel 8. This channel should be formed in the face of flange 7, which may be provided on the top of the valve body and also on the bottom thereof. Channel 8 should have inclined walls, or be made V-shaped, the better to receive special sealing ring 73 and co-act therewith. Ring 73 is preferably made of soft metal, and a cross-section thereof should be substantially elliptical in shape.

Before studs 4 are made up, with nuts 5, to hold together two or more complete blowout preventers into a single unit (such as is typically indicated in Fig. V), the opposed pair of channels 8 will have fitted therein a single special soft metal gasket ring 73. This ring will make and effect a circular seal between the bodies of two preventer valves. Ring 73 is a narrow sealing member, and it constitutes the only spacing element holding apart the pair of valve bodies employed to make up a dual assembly. This is a matter of importance. Through such arrangement the sealing effect of element 73 is materially increased as the fluid well pressure within the two communicating hollow bodies increases. The complementary and opposed pair of grooves or channels 8 are forced closer together, and between them they envelop more of ring 73 and force its further conformity to their confines.

As set out above, the side walls 1c of the valve bodies are vertically disposed and quite rigid, especially when reinforced with the bosses shown to provide additional metal stock for carrying studs 4.

The total surface area of side walls exposed to internal pressure is less than that of the top and bottom of the valve body. High pressure in the body thrusts top and bottom apart, especially at their centers (i. e., around openings 6).

'In operating plural blowout preventer assemblies, held together as a single unit, the tubing string or drill pipeor any other well pipe, which the well operator desires to have pass through aligned openings or passageways ing element 73, which element lies between two valve,

bodies, being held together by the studs 4, into both.

With well pipe 74 in place, and passing through opening 6 and through a plurality of blowout preventers arranged in unitary operation, the fluid pressure from the well casing will freely enter the hollow body of the lowermost preventer valve, coming through open flange 11 therebelow. It will fill the hollow body with pressure. Such pressure will pass around pipe 74 and through the annulus within special seal and spacer member 73, and ascend into the next uppermost hollow valve body and fill it with pressure.

Let it be assumed that the lowermost blowout preventer has its resilient valve heads 40 in retracted and not in sealing position. Then the rubber-like sealing heads do not contact pipe 74. Butlet us assume that exactlythe reverse is true of the uppermost blowout preventer unit in the assembly, and that resilient sealing elements 40 in the upper body have sealed around pipe 74 and have engaged the top of the uppermost valve body.

Under such conditions the full well pressure continues and is exerted throughout both of the hollow bodies of the pair of united valves. This results in a slight pulling outwardly of top and bottom parts, 1a and 1b, of eachof the valves. This slight deflection of the body is greatest in a field lying midway between the four posts 4. The

and is pressed bottom of the top valve body and the top of bottom valve vantage of the well pressure and allows it to make easier the moving of rams and the opening and closing of valves.

It is emphasized that no hyradulic power is used or needed to move or slide the rams, either forward to close a passage or backward to open a passage. The rams are easily moved manually. The use of hydraulic power in old type blowout preventers appears to have caused oil field operators to adopt and cling to the term ram. In this disclosure such term is to be understood to apply to slideable valve elements, operated manually, and moving in a zone of equalized pressure.

The rams which are slideably mounted within the hollow bodies of the valves are made up of a pair of opposed complementary universal slide members 38. Such members are slideable carriages. Each slide is provided with a receiving form, or recess 39, into which is fitted a resilient plastic or rubber-like valve head 40, which constitutes the primary sealing element of the valve. By advancing both slides to the center of the valve body, the two valve heads will be engaged, and the valve is closed. Thereupon the fluid well pressure may be conagainst well pipe 74, whenever the rams are moved into sealing position.

Resilient valve-head40 is provided with a side wall extension thereof, inclining upwardly from the upper face of the valve head and ending in a substantially vertical 7 lip of semicircular design. This side Wall, and especially the upwardly extending lip thereof, is shown. as at 41. It is made to extend normally a slight distance above the side wall of slide 38 on which the head is carried.

A retaining plate 50 is laid upon the upper face of the rubber-like member 40, and such plate comes to rest within the sloping inner face of side wall 41.

A pair of properly spaced recesses or sockets 51 are arranged in the under face of retaining plate 50, so that they will fit loosely over the free ends of retaining pins 52, which pins extend slightly above the central plane of the upper face of valve head 40.

At the center of the forward face of retainer plate 50 there is provided a semicircular opening 52, through which well pipe 74 may pass.

A suitable arrangement of a pair of opposed complementary slides, each carrying resilient valve heads and retaining plates, such as discussed immediately above, is shown in Fig. VIII, in which view the upper side of the opposing ram elements will be seen.

In Fig. VI the rams are turned over and looked at from the bottom. In such figure there will be seen the enlarged semicircular opening 48, in the bottom or bed of slide 38. It is to be noted that the slide opening 48 is made on a longer radius than that of the opening 43 in the resilient valve head 40.

To strengthen, support and prevent the undue cold flow of the rubber-like valve head 40, there has been provided a strong non-flexible and preferably metallic reinforcing plate 49. It is a semicircular plate, molded in the bottom of the resilient member 40. Plate 49 is made to constitute a reinforcing element, lying completely around pipe opening 43. Plate 49 is made on a greater radius than that required to describe the semi-circular opening 48 in the bed of the slide. Therefore, reinforcing element 49 extends somewhat over the floor of the slide and around opening 48 therein. This is indicated in Fig. VII.

Such construction and arrangement will prevent the downflow and outflow of the rubber-like material of resilient element 40 whenever great pressure is exerted on such element or upon retaining plate 50, or against the forward faces of element 40 when two of these opposing elements are forced together in sealing position at the point of greatest advancement of the rams.

Retaining plate 50 constitutes one form of a typical plate. Half plate 50a must be complemented by half plate 50/). Together these two partial plates constitute one complete circular plate, which may be considered as having been severed or cut into two complementary pieces.

The sockets 51 are so placed in each of the plates 50a and 50b that, when these plates are dropped upon the retaining pins 42 properly, there will be presented a lead face or guide face 53, which will extend outwardly and radially from semicircular opening 52, to assist in guiding pipe 74 into this opening when the rams are advancing toward sealing position.

The other forward face 54 of each plate 50 sets back from the forward face of the resilient member 40 thereunder. By such arrangement plate 50a actually comes to rest upon and helps strengthen both of the valve heads 40 found in a complete ram. Complementary plate 50b does the same kind of an overlapping job.

Typical retainer plate 50 may be either one of a pair of complementary plates, being 50a and 50]). All retainer plates are so arranged and provided with calculatedly located sockets 51 that each plate assists in retaining two complementary rubber-like elements 40, which may be elements 401: and 40b.

Further dual support of elements is provided by the arrangement of extension 44 on the floor of each complementary slide 38. Such extension helps to support each of the complementary and opposing valve heads 40 when the rams are closed.

While the rams are being movedtogether, the extension 44, which is provided with a beveled face 44a, so as to lead angularly toward semicircular recess 43 in element 40, will provide one side of a radial guide. Such guide will properly urge pipe 74 into the circular recess 43, as the rams are being closed about such pipe.

Opposite the V-shaped extension 44 on one slide, there is provided a V-shaped recess 45, to constitute a receptacle on the floor of the opposing slide. Such recess will receive the pointed end of extension 44 of the opposite slide.

The particular placement of sockets 51 will cause face 54 of retainer plate to be set inwardly from the forward vertical face of member 40, when plate 50 is dropped over pins 42.

In the same way, and by utilizing the similar means (sockets 51 and retainer pins 42), the face 53 of each retainer plate is thrown forward to constitute angular guide means which will guide pipe 74 into recess 43. The net result of such arrangement is that two angular guides, one on the base of the slide (being guide face 44a) and one on the retainer plate 50 (being guide face 53) together gently urge pipe 74 into the proper recesses (43 and 52) as the rams are being closed.

Appropriate construction is arranged externally of each end plate 14, and therefore outside of the valve body, to provide means for rotating the tubular valve stem 21 and thereby urging inwardly (toward one another) a pair of opposing complementary rams. Reversing the direction of rotation of such means will cause the retraction (toward the end plates) of the two complementary rams.

A suitable lever, crank or wheel may be rigidly but removably attached to the external part of valve stem 21.

A preferred form of means for rotating tube 21 is shown in the drawings as a handwheel 1.8, which may well be provided with radial spokes extending outwardly of the periphery of the wheel, somewhat as a mariners pilot wheel is arranged. The hub 19 of the wheel may be made to extend inwardly toward the valve body so as to form a collar socket having fiat inner walls, such as a foursided or a six-sided socket would present.

Tube 21 is closed at its outer end with a solid head 21a, which is provided with flat outer sides, square 6r hexagonal, to fit into the hollow socket of hub 19. This hob is firmly made up with head 2111 by providing bolt 20 to pass entirely through such members and be secured outwardly with a nut whereby handwheel 19 and tube 21 are made to rotate together.

Tubular recess 22 is so provided in tube 21 as to furnish a recess into which the externally threaded feed screw 34 may retreat when handwheel 18 is so rotated as to retract the rams. The open end of tube 21 has a thickened and internally threaded wall for a limited distance to receive the threads on rod 34.

Therefore, it will be seen that the valve stem is made of two telescopic members, the tube 21 and the threaded rod 34. This arrangement provides externally of the valve body a non-extensible or non-rising valve stem. Such construction is valuable because it is desired to have the handwheel as close to the valve body as is reasonably possible. This prevents the valve stem from so extending as to invite deflection or breakage.

Passage 23 is provided through the center of end plate 14, and this passage receives tube 21 and allows its rotation therein.

To prevent horizontal movement of rotatable member 21, there is threaded around it retaining ring 24, and such ring is held firmly to member 21 by the use of set screw 25. Bushing 26 rides freely around tube 21 and against the outer face of end plate 14. It provides an anti-friction bushing between the end plate and retaining ring 24.

Passage 23 is sealed off around the rotatable tubular member 21, of the valve stem, by providing suitable resilient sealing rings, such as the 0 rings 27. They should be provided in plural numbers and partly recessed within the outer wall of tube 21 and allowed to extend and press outwardly against the smooth walls of channel 23. Thus the escape of fluid pressure from the valve body chamber 56 through channel 23 is prevented.

A continuous channel 29 is provided in the inner face of end plate 14, and such channel will lie opposite the finished end face of hollow valve body 1. Into channel 29 a resilient gasket 28 is pressed and held between such end face and plate 14. Gasket 28 is called the racetrack gasket, having the shape of a rectangle with the corners rounded off. It is a continuous gasket and it is caused to press in three directions, laterally into the channel and opposedly against the two members, 1 and 14, which are joined about this gasket. Their line of joinder must never leak.

A perforated plate 30 is so placed as to continuously hold gasket 20 in recess 29 and prevent it coming out into the hollow space of the valve body. Such plate extends transversely across a hollow recess lying around passage 23 and provided the inner face of plate 14.

Threaded valve stem rod 34 becomes a feed screw when it is made up into the threaded open end of recess 22 of hollow stem 21, upon the rotation of the latter. The free end of rod 34 terminates in a head 35. This head drops loosely into a slotted bracket 36, which is rigidly attached to the end wall of slide 38. The bracket is so made as to provide channel 37 therein to receive head 35. This head cannot pass through the slot in the bracket. Head 35 may not be removed from channel 37 until slide 38 is taken out of the valve body 1. Therefore, slide 38 always moves forward or backward in response to the movement of valve rod 34.

The inner end of tube 21 terminates in an outwardly extending flange which provides shoulder 32. Between this shoulder and a complementary shoulder or annular face 33, arranged inside of end plate 14, and surrounding the open end of passage 23, there is provided a loosely disposed bearing ring or washer 31. Such construction lessens friction in the rotation of tube 21, and it further prevents the tube being withdrawn through passage 23 in face plate 14. Thus no horizontal or sliding movement is allowed in tube 21.

It is to be noted that the open and flanged end of tube 21 is provided with internal threads on rod 34. It is further to be noted that the length of rod 34 is such that it may never be expelled from the open end of tube 21, regardless of the extent of rotation of the latter. This is so because slide 38 may not progress further than the approximate center of the valve body. The limit of the travel on this slide is not only fixed by pipe 74 passing through the forward face thereof, but such travel is further limited by an opposing complementary slide. Even if pipe 74 and the opposing slide were both absent, the initially moving slide is prevented from moving further inwardly by striking against set screw boss 65. This screw boss extends its freer end into recessed guide slot 47, provided on the outer face of long arm 46 of slide 38, whenever the rams are in contact and the valve is closed. i

The entire open and hollow space within the valve body 1, extending between the end plates 14, may be considered as the valve space, and it is shown as at 56. Such space has its greatest height immediately under the slightly thinned sections 55 of the top of the body, one such section being at each end of the body.

Depending slightly from and across the under face of the top of the body 1, is the dropped ceiling 57. It is something in the nature of a very short depending boss. It has a continuous flat under surface, which is smoothly finished. It furnishes a sealing face against which the plastic element 40 flows when squeezed, at the time the valves are fully closed. Plate 50 is elevated against the face of ceiling 57 by the squeezing of plastic valve head 40, when the rams are brought together.

Before a valve head is brought into complete engagement with an opposing valve head, and around pipe 74,

there is normally left, between the upper face of plate 50 and the lower face of ceiling 57, the space 63. This space disappears when the rams are advanced to position of complete valve closure. However, until that position has been reached, this space has the advantage of allowing the rams and slides 38 to loosely move almost into position of contact with one another without any undue friction while moving.

The surface of the bottom 1b, of the valve body 1, is provided with a level floor 58, which extends across the valve chamber. On this floor is provided a pair of rails for each slide 38. These rails are elevated slightly above the floor 58, by being caused to extend upwardly therefrom. Each rail includes an inclined section 59 and a flat section 60, the latter being nearest the center part of the valve body. Beyond the flat end of the rail there is provided on floor 58 an upwardly extending boss 61, which will help support slide 38 in its most advanced position. Between boss 61 and the forward and level end 60 of each rail, there is a clearance space 62, allowing for free passage therethrough of fluid pressure, and lessening the surface by which the under side of slide 38 makes contact with supporting members 60 and 61 when in position of valve closure.

By rotating handwheel 18 the hollow tube 21 of the valve stem is rotated, but tube 21 does not slide. It may turn in passage, but it may not otherwise move in any direction. It does not go deeper into the end plate 14, nor is it caused to be extended therefrom by any rotation of' handwheel 18. I

However, the rotation of valve stem tube 21 causes the threading thereinto of feed screw (threaded valve stem rod) 34, when handwheel 18 is turned in one direction.

Screw member 34 is partially extended out of tube 21' and into the open valve chamber 56 when handwheel 18 is turned in the opposite direction.

Fig. VII shows the approximate location of a ram at its point of furthest retraction. In this position the bed of slide 38 rests on the inclined section 59 of the slide rails,

and the forward face of the ram is pitched up at a slight angle. Such is easily permitted by the loose toggle-like joint made between rod 34 and its head 35, on the one hand, and slotted bracket 36 on the other. The bracket is firmly aflixed to the back end of slide 38 and moves therewith.

In Fig. V the valve stem has been so rotated as to cause its extension. Rod 34 has advanced somewhat into the valve chamber space. After traveling up the inclined rail 59 the bottom of the slide has come to rest on the level section 60 of the slide rails, and the entire ram has come into horizontal position. space 63 above the top of the ram is clearly evident. At this time the upper face of plate 50 lies slightly below the surrounding lip 41 of resilient member 40.

When two opposing rams make initial contact the position of the elements of one such ram may be understood upon examining Fig. IX. Further advancement of two rams into tighter engagement along their meeting faces will cause the squeezing of resilient valve head 40,

somewhat in the manner shown in Fig. X. This resilient material will flow upward slightly increasing the height and narrowing the width of lip 41. Plate 50, meeting an opposite plate of like character will be forced backward,

ly slightly above the top of pin 42. Thereupon the space 51 behind the pin will be slightly entered by the cold flow of the material of resilient member 40, somewhat.

At such stage the plates 50a and 50b (being but complementary and opposing typical plate members 50) will meet together along a common face on each side of pipe 74.

At this stage the clearance As shown in Fig. XI, especially in the dotted lines therein, the pointed end 45, of an extended part of the bed of slide 38, will approach near to the V-shaped recess 44, in the bed of the opposite slide. However, these metallic members never come into actual contact, as indicated by the spaced relation of the dotted lines in Pig. XI. Maximum compression of opposing elements 40 is reached before the beds of opposing slides 38 can actually touch.

Fig. XII shows the approximate relative positions of two opposing resilient valve heads after they have come into contact and the squeezing of these resilient elements has begun. The most immediate effect is the shortening and thickening of the main horizontal body of each resilient element, and the consequent upward extension of lip 41. These operations raise plate 50. Therefore, when valve closure has been completed it will be found that both plate 50 and lip 41 have been forced most tightly against depending boss 57. Once a valve has been closed it is kept closed and better sealed by the relatively great fluid pressure of the well which is exerted throughout the valve chamber 56. This force drives the rams upwardly against ceiling 57 in the top of the hollow valve body.

Fig. XII actually shows a modified form of resilient valve heads and of retaining plates thereon. Such valve heads and retaining plates are given the name of blanks. They are not provided with any central hole or passageway through the lead face of opposing blank valve head members 71. Neither is there any hole through blank retaining plates 70, for the passage of any pipe, such as pipe 74.

In the modified form of valve heads and retaining plates shown in Fig. XII, it will be noted that the bottom reinforcing plates 72 are not provided with any holes therethrough. Therefore, the valve head construction shown in Fig. XII, with associated members, modified as needed, constitute the type of valve closing elements and mechanism which is frequently used in the lowermost of a pair of blowout preventer valves.

With absolute safety the tubing or drill stem 74 may be sealed around by the uppermost of the twin blowout preventers, the uppermost being of standard design, such as shown in Figs. IV and V. Such pipe 74 may be raised or lowered in the well provided the modified valve heads 71 (shown in Fig. XII) are in retracted position in the lowermost preventer. When pipe 74 has been lifted upwards and out of the well to a point immediately above the top of the lowermost blowout preventer, then the blank valve heads 71 are forced together, and the central pipe opening in the body of the lowermost valve is absolutely sealed off.

No well pressure may thereafter enter the topmost of a pair of blowout preventers arranged together as a twin unit, when the lowermost is equipped with blanks and operated as aforesaid.

Since it would be advantageous to allow fluid pressure within the hollow body of a valve to flow freely into thehollow section 22 of valve stem tube 21, there has been provided a slot 64 to run longitudinally across the female threads in the flanged end of member 21. Such arrangement equalizes pressure around valve stem rod 34, and allows it to travel most easily in and out of the recess 22. It is never hampered by any unequal pressures.

It will be observed that the rams are allowed to fit most loosely in the valve chamber. At all times they are loose until they are in complete sealing engagement. The inner surfaces and faces of valve housing body I therefore require practically no machining. This allows great savings in labor, and presents a substantial advance over art hitherto practiced. The contacting edges of the faces of end plates 14 are machined. The engaging faces at each end of valve body 1 are machined. Depending boss 57 is made smooth by machining. Supporting bosses 61 are similarly machined, and so are the tracks 59 and 60, up which slides 38 move. No other 12 machine work is necessary inside body 1 or inside the end plates 14.

However, in order to make most exact and precise the centering and proper location of rams, and particularly slides 38, when they are going into and finally reach maximum engagement, there has been provided rather inexpensive but most accurate and dependable guides, arranged through the side walls 10 of the valve body.

Threaded holes, on each side wall, are made to receive set screws 65 and 66. These holes are enlarged on the outer face of the walls to receive the heads of these screws. Whenever such screws have been placed at the exact degree of desired projection, inwardly of the Walls 10, the heads of the screws are welded to the wall and the outer ends of these holes are closed up with welding material 67, as indicated in Fig. VI.

Slotted recess 47 is provided on the end of long arm 46 of a typical slide 38. Into recess 47 the longer set screw 65 is introduced until contact has been made with the bottom of the recess. Then shorter set screw 66 is introduced until it strikes the opposite end of arm 46. Such operation is carried out on each side wall of the valve body 1. Each of the two opposing slides are properly placed in valve closing position, and the set screws are adjusted thereagainst. Such adjustments as may be necessary are made until the set screws limit and fix and define the exact place and position where the rams will come to rest when they are in maximum sealing engagement. Adjustment by the use of set screws, 65 and 66, is most accurate and it is most cheaply attained. When it has been reached, then such adjustment is made permanent because of the use of welding 67 to finally fix the positions of adjustment in most exact manner.

Through the end plates 14 there may be provided passages 68, threaded to receive plugs 69. Passages 68 are provided for the purpose of cleaning out the valve body Whenever desired by forcing fluid therethrough. Also by removing plugs 69, conduits may be attached to the passages through the use of which well fluid may be freely circulated into, through and out of the open and hollow space within valve body 1. This matter is one of great utility to an operator in the oil field. The cleaning of valves without dismantling them, and the circulation of well fluid through such valves without removing them, is of great advantage and benefit and results in the saving of much labor.

It is of importance that in this blowout preventer the rams and slides which carry the resilient valve heads are spaced from the side walls of the hollow valve body at all times. They are also elevated above the floor of such body at all times, riding on rails, and/or resting on small spaced bosses.

likewise these slideable members make no contact with the top of the body casing until final closing of the valve is attained. Therefore, well fluid flows freely throughout the hollow valve body and about the rams.

The greater part of the walls, floor and top of the valve body are never touched by any moving parts whatever; and such surfaces are left unfinished and without machine work thereon, such being simply unnecessary. The resulting savings in machine shop labor are relatively enormous, and the operation of the valve is made unusually simple and easy and accurate. Friction on moving and sliding parts is reduced to a merest minimum.

The slides carrying resilient rubber-like valve heads are so constructed as to afford greatest protection to such heads and avoid friction thereon. They are protected by the metallic box slide, having a bed and side and end walls, arranged to shield them. The overlapping extended side arms 46 give added protection. The top metallic plates 50 further shield the resilient members.

I claim:

1. In a well blowout preventer a hollow valve body including a substantially fiat top spaced apart from a substantially like bottom by two substantially rectangular side walls and closed at each end with an end plate; a passage arranged centrally of the top of the body and a like passage so arranged in the bottom thereof, the openings being in vertical alignment; a pair of opposed slideable rams carried within the valve body; valve stem means loosely attached to each such ram and extending through an end plate to be operable from without the body to advance and retract a ram; a circular groove provided in the upper face of the body to surround the passage therein; a circular groove provided in the lower face of the body to surround the passage therein; each such groove being adapted to receive a sealing ring and hold apart a pair of valve bodies when such ring extends into a groove in the top face of one body and the bottom face of another; and a plurality of stud receiving passages arranged through the body outside of the hollow portion thereof, such passages being arranged in a square pattern about the central passages.

2. In a plurality of blowout preventers stacked one over the other, each preventer having a hollow box-like body with top and bottom walls of greater combined area than the combined area of the end and side walls, and the bodies having coinciding passages arranged vertically therethrough; coinciding annular grooves about the passages on the adjoining faces of the connected preventers; and a sealing ring positioned in the coinciding grooves the adjoining faces of connected preventers being spaced and held apart by said sealing ring; the said preventers being joined together by attachment means positioned outside of the hollow portions of the bodies, whereby when pressure is increased in the blowout preventer bodies the bottom and top walls thereof flex and compress the sealing r1ng 3. In a plurality of blowout preventers stacked one over the other, each preventer having a hollow box-like body with top and bottom walls of greater combined area than the combined area of the end and side walls, and the bodies having coinciding passages arranged vertically therethrough; coinciding annular grooves about the passages on the adjoining faces of the connected preventers; a sealing ring positioned in the coinciding grooves the adjoining faces of connected preventers being spaced and held apart by said sealing ring; and a plurality of studs passing through the bodies outwardly of the hollow portion thereof.

4. In a blowout preventer, a slide comprising; a body; a pair of pins extending upwardly from the bottom of the body; resilient sealing material resting on the body and being detachably held in place thereon by the pins; a retainer plate; sockets arranged in the lower side of the retainer plate in which the pins are loosely inserted, such sockets being larger in diameter than the pins so that the retainer plate may move relative to the sealing material when positioned thereover.

5. In a blowout preventer, a slide comprising; a body; a pair of pins extending upwardly from the bottom of the body; resilient sealing material resting on the body and being detachably held in place therein by the pins; a retainer plate; sockets arranged in the lower side of the retainer plate in which the pins are loosely inserted, such sockets being larger in diameter than the pins; the sockets in the plate being arranged so that a portion of the plate protrudes beyond the sealing material to form a guide for guiding a pipe toward the center of the sealing material; and an extension arranged on the bottom side of the slide opposite the protruding portion of the plate arranged to guide a pipe toward the center of the sealing material.

6. In a blowout preventer, a slide comprising; a body; resilient sealing material resting on said body; a retainer plate positioned over the resilient sealing material; an extending leg on the side of said body arranged to form a side wall adapted to overlap a complementary slide and adapted to extend beyond the resilient sealing material carried by such complementary slide when engaged therewith.

7. In a blowout preventer, a hollow elongated body having a vertical passage therethrough and a horizontal slideway therein; a pair of complementary rams slideably arranged in the slideway; a plurality of adjustable bosses arranged on the inner side walls of the slideway adapted to guide the rams into sealing engagement and maintain them in spaced relation to such walls.

8. In a plurality of blowout preventers stacked one over the other, each preventer having a hollow box-like body with top and bottom walls of greater combined area than the combined area of the side walls; and the bodies having coinciding passages arranged vertically therethrough; coinciding annular grooves about the passages on the adjoining faces of the connected preventers; a sealing ring positioned in the coinciding grooves the adjoining faces of the preventers being spaced and held apart by the sealing rings; and four studs passing through the bodies outwardly of the hollow portions thereof for securing the bodies together, such studs being arranged in a square pattern.

9. In a blowout preventer; a body; a horizontal slideway arranged through the body; a vertical passage arranged through the body; complementary rams slideably arranged in the slideway and arranged to close the vertical passage; the rams being spaced from the walls of the slideway to allow pressure fluid circulation from the well about the inner side walls of the body; and each rarn including a slide having a rigid bed, a sealing element loosely resting on said bed, a cover plate loosely resting on such element, and vertical pins rigidly fixed in said bed and extending upwardly through such element and into the plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,713,364 Arbon May 14, 1929 1,891,686 Nicks Dec. 20, 1932 2,060,252 Shaffer Nov. 10, 1936 2,090,206 King Aug. 17, 1937 2,136,465 Pranger Nov. 15, 1938 2,154,955 Mueller Apr. 18, 1939 2,162,018 Inge June 13, 1939 2,218,093 Penick Oct, 15, 1940 2,278,050 Allen Mar. 31, 1942 2,592,197 Schweitzer Apr. 8, 1952 2,593,793 Rector Apr. 22, 1952 

